Spark plug for explosive engines



Patented Qct. 16,1923.

snares star 5P A ENT f-OZFF-ICE;

ALBERT E. EHMKE, or srLvEn on-nnK, new YORK, assreNoR-or, ONE-THIRD TO CHARLES W. EHMKE AND ONE-THIRD TO cnnnx, new roan.

ALBERT B. CHAPMAN, BOTH 015 SILVER srnax PLUG non nxrnosrvn ENGINES.

Application 'filed October 14, 1921. Serial Ho. 507,666.

T 0 aZZ whom it may concern: r r 7 Be it known that I, AL ERT E. EHMKE, a citizen of the United States, residing at Silver Greek,'in the county of Chautauqua and State of New York, have invented'certain new and useful Improvements in Spark Plugs for Explosive Engines, of which'the following is a specification.

My invention relates to improveme'ntsin spark plugs for explosive engines, and more particularly to what are termed multiplegap spark plugs. f

The primary object of this invention is the production of a spark plug having a plurality of sparking gaps, all of which are preferably exposed so that the explosive fuel delivered to the combustion chamber of the engine to which the spark plug is applied will come in direct contact with the spaced sparking elements forming said gaps.

A further object of my invention is the provision of'a spark plug in which a plurality of 'sparkga'ps are provided and'so arranged to causea series of intense annular'sparlrs which will effectively ignite the explosive mixture drawn into the engine.

A still further ob 'ect is to so construct the sparking elements Iorming the plurality of spark gaps, that fouling of any spark gap of the plurality or series will assure proper operation of the engine, as a singlespark gap properly functioning will cause the spark plug to operate as efficiently as the common spark plugs now in use when actlng at their highest efliciency; .although'there willbe a reductionfrom maximum efficiency when any of the spark gaps become foul.

The invention consists in the'novel features of construction and inthe arrange ment and combination of parts to be hereinafter described, and more particularly pointed out in the subjoined claims.

In the drawings Figure 1 is a side elevation of a spark plug constructed in accordance with my 1nvention.

Fig. 2 is an enlarged vertical section of the spark plug showing the in'ner'end thereof threaded into an engine cylinder.

Fig. 3is a detached perspective view of the insulation element carrying one or more of the sparking elements.-

the innermost port.

Fig. 5 is an thelower end of the axial electrode which sparking element andit's sup- 4 is a detached perspective view of:

inverted perspectiveview of I extends through the insulation core, with V I one of the sparking elements secured thereto. Fig; 6 is an enlargedtransverse section taken on line 66, 'Fig. 1. Y; I

In Fig. 2 of the drawing, the numeral 7 designates one of the walls of an engine cylinder into which. my improved spark plug is shown" threaded. The spark plug comprises a suitable shell or casing 8-hav1ng a porcelain or other'insulation core '9 extending. thereinto, said core being retained in said shell or casing by a nut 10. The core 9 has an enlarged-portion 11 which bears against a shoulder 12 in the shell or casing, and between the inner end of the nut and said enlarged portion, a gasket l3is interposed, thus making a tight joint I to preventthe escape of gases through the spark plug shell or casingq This, however, forms no part'of my invention andzthe shell or casing and 'core may becon structed and secured "together in any other approved manner;

As is common in spark plug constructions, the porc'elain'or other insulationcore!) has 'an electrode 'lajextending axially therethrough, the outer end of which projects from the outer or upper .end of said core and has the usual clamping nut 15 applied thereto by means of which the terminalof a current wire 16 is secured'to the plug.

The porcelain or insulation core, 9 terminates at its inner end a short distance from the inner end of the shell or casing 8, and the innerend 'ofsaid axial electrode isreduced to form an inwardly facing shoulder 17.

socket 19 which has a central bore threaded througha portion of its length toreceive the externally threaded reduced inner end of the Said reduced portion is externally- 7 threaded, as at 18, onto'which is applied a electrode 14., said-bore being of'greater length than the" lengthof said reduced portion so as toreceive the inner end of a slender insula'tion'element 20, whichjniay be constructed of lava, mica, or porcelain properly fired. Preferably the inner end of the socket 19 is in a plane outside or" the spark plug shell or casing 8. The socket 19, as will appear hereinafter, forms one of the plurality of sparking elements, and may be said to serve as part of the axial electrode 14:. The opposite end of the insulation element 20 is fitted into a socket 21, which serves as a sparking element, said socket having a transverse opening 22 therein, through which a yoke 23 formed or wire is passed, said yoke having its ends inserted into sockets 2 formed in the end of the spark plug at diametrically opposite points. The yoke 23 serves as a current-conducting support and comprises a transverse member :25 and side members 26, the transverse member being-bentinwardly between its ends, as at 27, thus forming more or less sharplycurved or angular corners at the points of connection of said transverse member to said side members. Therefore, oil accumulating on the cylinder wall or on the edge of the shell or casing of the spark plug may travel inwardly along the side members and drip from the curved or angular portions 28, and as these angular portions are at the innermost points of the yoke, oil is prevented from traveling alongthe transverse member 25 and reaching the spark gaps, thus preventing fouling of the spark plug; it being assumed of course that in most cases, the spark plug will be used in a vertical position or at only a slight angle to the vertical and that said sharply-curved or angular portions will consequently be the lowest points of the spark plum Secured to the slender insulation element 20 is one or more sleeves 29 which serve as sparking elements. In the drawing 1 have shown two sparking elements 29 secured to the slender insulation element and these are spaced apart. The inner or the two sparking elements 29 isspaced irom the socket 21 while the outer is spaced from the socket 19, thus forming a plurality of spark gaps 30 between all sparking elements.

, lhe ends of the yoke 23 are detachably retained within the sockets 2 in the shell or casing, thus permitting the ready removal of the slender insulation element 20 with its attached sleeves 29 from the socket 19, it being simply necessary to pull inwardly on the yoke or support, which will carry the socket or sparking element 21 with it, leaving the insulation memberwith its sparking elements .29 hanging from the socket 19, unless'the upper end of said. insulation element hasbecome worn from constant removal and replacement and so loosely fits the socket l9that it cannot be retained thereby, in which case the insulation element will be withdrawn when removing the yoke and its socket 21.

The spark gaps 30 are of circular or annular formation and extend around the insulation element 20, thus when current is passed through the spark plug, a series circular sparks are created, which extend from the sparking element to an adjacent sparking element, thereby providing intense and extensive sparks, which will assure powerful explosion of the explosive mixture within the engine cylinder.

The device shown and described is simple, inexpensive, and highly efiicient, and assures proper operation of a motor under all running conditions, as the fouling of any spark ga or gaps less than the total number emp oyed, will merely reduce the elliciency without effecting the smooth running of the engine and as constructed, the spark plug canbe easily cleaned without resorting to the removal of the core and other parts of the plug, as invariably necessary in spark plugs now in use.

Having thus described my invention, what I claim is l. A spark plug comprising a shell or casing, an insulation core having a portion thereof held within said shell or casing and extending from one end thereof, an electrode extending axially through said core and projecting from opposite ends thereof, one end of said electrode being adapted to have a current-conducting wire attached thereto, a socket secured to the other end thereof, a slender insulation element having one end held within said socket, a support secured to the inner end of said shell or casing, a socket carried by said support and having the other end of said slender insulation element held therein, and a sparking element on said slender insulation member between said sockets and spaced therefrom to provide a plurality of spark gaps.

2. A spark plug comprising a shell or casing, an insulation core extending into secured to said shell or casing, an electrode extending axially through said core and projecting inwardly beyond the inner end of said shell or casing, a wire support comprising a transverse member and two side members and having its free ends secured in the inner end of said shell or casing, a slender insulation element receiving support from said electrode and said support, and a plurality of sparking elements on said slender insulation element spaced from each other to provide a sparking gap or gaps.

3. A spark plug comprising a shell or casing, an insulation core extending intosaid shell or casing, an electrode extending axially through said insulation core, a current conducting support secured to the lower of said shell or casing, and a sparking element between and carried by said electrode and said current conducting support.

4-. A spark plug comprising a shell or casing, an insulation core held therein, an electrode extending through said core and having an externally-threaded reduced inner end, a socket threaded onto the reduced in ner end of said electrode, a U-shaped member formed of wire having opposite ends secured into the inner end of said shell or cas ing, a socket arranged centrally on said U- shaped member in line with the socket on ing axially through said insulation core, a

support formed of wire having a transverse member and two side members arranged at an angle to said transverse member, said side members having their ends entered into said shell or casing at the inner end thereof and having its transverse member bent inwardly from its intermediate portion, a socket having a transverse opening through which the transverse member of said support is passed, a socket secured to the inner end of said electrode, a slender insulation element having opposite ends entered in said sockets, and sparking elements on said insulation memher spaced apart to provide spark gaps with the sparking elements adjacent said sockets spaced therefrom to provide additional spark gaps.

6. A spark plug comprising a shell or casing having sockets in its inner end at diametrically iopposite points, a substantially U-shaped support formed of wire having opposite ends entered in said sockets, an insulation core secured within said shell or,

casing, an electrode extending axially through said insulation core, asocket secured to the inner end of said electrode, a socket on said support having its axis coincident with that of the socket secured to said electrode, a slender insulation member having opposite ends entered in said Sockets, and sleeves earned by said slender insulation member and being spaced apart, the sleeve adjoiningv the socket on said electrode being spaced therefrom and the sleeve ad- Joining the socket on said support being spaced therefrom, the spaces between said sleeves and between said sleeves and said socket forming spark gaps.

In testimony whereof I afiix my signature.

ALBERT E. EHMKE, 

